Add devcontainer for easier external contribution (#18694)

* add devcontainer

* add readme

.devcontainer/README.md

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+# Dev container configurations
+
+This directory contains the configuration for dev containers, which is used to
+initialize the development environment in **Codespaces**, **Visual Studio
+Code**, and **JetBrains IDEs**. The environment is installed with all the
+necessary dependencies for development and is ready for linting, formatting, and
+running tests.
+
+* **GitHub Codespaces**. Create a codespace for the repo by clicking
+    the "Code" button on the main page of the repo, selecting the "Codespaces"
+    tab, and clicking the "+". The configurations will automatically be used.
+    Follow
+    [this guide](https://docs.github.com/en/codespaces/developing-in-a-codespace/creating-a-codespace-for-a-repository)
+    for more details.
+
+* **Visual Studio Code**. Open the root folder of the repo in VS Code. A
+    notification will pop up to open it in a dev container with the
+    configuration. Follow
+    [this guide](https://code.visualstudio.com/docs/devcontainers/tutorial)
+    for more details.
+
+* **JetBrains IDEs**. Open the `.devcontainer/devcontainer.json` in your
+   JetBrains IDE. Click the docker icon to create a dev container.
+   Follow
+   [this guide](https://www.jetbrains.com/help/idea/connect-to-devcontainer.html)
+   for more details.

.devcontainer/devcontainer.json

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+{
+    "image": "mcr.microsoft.com/vscode/devcontainers/python:3.10",
+    "postCreateCommand": "sh ./.devcontainer/setup.sh",
+    "customizations": {
+        "vscode": {
+            "settings": {
+                "python.testing.pytestEnabled": true,
+                "editor.formatOnSave": true,
+                "editor.codeActionsOnSave": {
+                    "source.organizeImports": true
+                },
+                "[python]": {
+                    "editor.defaultFormatter": "ms-python.black-formatter"
+                },
+                "editor.rulers": [
+                    80
+                ]
+            },
+            "extensions": [
+                "ms-python.python",
+                "ms-python.isort",
+                "ms-python.flake8",
+                "ms-python.black-formatter"
+            ]
+        }
+    },
+    "features": {
+        "ghcr.io/devcontainers/features/github-cli:1": {}
+    }
+}

.devcontainer/setup.sh

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+sudo pip install --upgrade pip
+sudo pip install -r requirements.txt
+echo "bash shell/lint.sh" > .git/hooks/pre-commit
+chmod a+x .git/hooks/pre-commit